JP3737347B2 - Optical probe element and recording / reproducing apparatus using the optical probe element - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical probe element that narrows light below a diffraction limit and a recording / reproducing apparatus using the optical probe element.
[0002]
[Prior art]
In recent years, a scanning tunneling microscope (STM) capable of directly observing the surface state of a substance on an atomic scale has been developed. In addition, a scanning atomic force microscope (AFM) and a scanning magnetic force microscope (MFM) have been developed by applying the principle of STM. In these microscopes, the probe with a sharp tip and the surface of the substance are placed close to each other to detect the tunnel current flowing between them, or the atomic force and magnetic force acting between them. .
[0003]
Furthermore, a photon STM using an optical probe having a sharp pointed tip has been developed. In Photon STM, light is incident from the surface of a sample, and evanescent light that oozes out on the surface of the sample is detected.
[0004]
Various apparatuses for recording and reproducing information on an atomic scale region using the principle of STM have been proposed. Also, attempts have been made to record and reproduce information using the narrowed light by using the principle of photon STM to narrow the light below the diffraction limit (for example, Appl. Phys. Lett. 61 (2) , 13 July 1992 P.142).
[0005]
FIG. 27 shows a recording / reproducing apparatus using an optical probe.
[0006]
The optical probe 803 is formed at the tip of the optical fiber 800. The optical fiber 800 is attached to a movable support portion 822. A drive unit 821 for moving the support unit 822 is fixed on the base 820. The recording medium 810 is also fixed on the base 820. The optical probe 803 can be moved to a desired position on the recording medium 810 by moving the support portion 822 by the driving portion 821.
[0007]
The recording medium 810 includes a transparent substrate 811 and a recording layer 812 formed on the transparent substrate 811. The optical probe 803 is arranged so that the tip thereof is close to the recording layer 812.
[0008]
When recording information, light whose intensity is modulated in accordance with the information is introduced into the optical fiber 800 and is narrowed below the diffraction limit by the optical probe 803. Thereby, information can be recorded on the recording layer 812 with high density.
[0009]
A method for manufacturing the optical probe 803 is shown in FIG.
[0010]
First, as shown in FIG. 5A, a part of the optical fiber 800 is heated until it is almost melted. In this state, the optical fiber 800 is pulled left and right as shown in FIG. The red hot part 801 of the optical fiber 800 extends to the left and right and is cut as shown in FIG. As a result, an optical probe 803 having a sharp tip is obtained.
[0011]
[Problems to be solved by the invention]
However, the above-described conventional configuration has a problem that it is difficult to make the tip diameter of the optical probe 803 constant, and therefore, the optical probe 803 having the same standard cannot be mass-produced.
[0012]
Further, when a plurality of pieces of information are simultaneously recorded and reproduced using a plurality of optical probes 803..., The distance between each optical probe 803 and the recording medium 810 is kept the same in the conventional configuration. It has the problem of being difficult.
[0013]
[Means for Solving the Problems]
The present invention In order to solve the above-described problem, the optical probe element according to the present invention includes an optical probe including a substantially conical protrusion made of a light-transmitting material and a reflective film formed on a conical surface of the protrusion except for a tip portion of the protrusion. Is formed on one surface of a flat substrate made of a light-transmitting material, and the other surface of the flat substrate is planar, and the projection of the optical probe is formed by etching one surface of the flat substrate. The converged light collected by the condensing lens is incident on the planar substrate from a planar portion facing the projection of the optical probe, passes through the planar substrate, and is incident on the projection. It is characterized by.
[0014]
The present invention In order to solve the above problems, the optical probe element according to the above In this optical probe element, a plurality of optical probes are formed on one side of a flat substrate.
[0015]
The present invention In order to solve the above problems, the optical probe element according to the above In this optical probe element, the same number of condensing means as the optical probes, each of which is focused on each optical probe, is formed on the plane substrate surface on which the optical probe is not formed.
[0016]
The present invention In order to solve the above-described problem, the recording / reproducing apparatus according to the present invention includes a light source and an optical probe element that narrows light from the light source to minute light having a diameter equal to or less than a diffraction limit, and irradiates the recording medium with minute light. In the recording / reproducing apparatus for recording / reproducing information, the optical probe element includes a substantially conical protrusion made of a translucent material and a reflective film formed on the conical surface of the protrusion excluding the tip of the protrusion. The optical probe is formed on one side of a flat substrate made of a light-transmitting material, the other surface of the flat substrate is planar, and the projection of the optical probe is etched on one side of the flat substrate. The converged light converged by the condensing lens is incident on the planar substrate from the planar portion facing the projection of the optical probe, passes through the planar substrate, and enters the projection. Incident It is characterized by a door.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS. 1 to 16 as follows.
[0018]
As shown in FIG. 1, the recording / reproducing apparatus of the present embodiment includes a light source 402, a collimator lens 401 that changes the light from the light source 402 into a parallel beam 5, an optical probe element 20 having an optical probe 3, and an optical probe. 3 includes a condensing lens 4 for converging the parallel beam 5, and a support 202 to which the condensing lens 4 and the optical probe element 20 are attached.
[0019]
The recording / reproducing apparatus is further disposed on the optical path between the drive unit 201 that moves the support unit 202, the base 200 that fixes the drive unit 201 and the recording medium 300, and the collimator lens 401 and the condenser lens 4. A beam splitter 400 that transmits the parallel beam 5 from the collimator lens 401 and reflects the return light from the recording medium 300, and a photodetector 403 that detects the return light reflected by the beam splitter 400.
[0020]
The recording medium 300 includes a transparent substrate 301 and a recording layer 302 formed on the transparent substrate 301, and is fixed on the base 200 with the recording layer 302 facing up. The optical probe 3 is arranged so that the tip thereof is close to the recording layer 302.
[0021]
As shown in FIG. 2, the optical probe element 20 includes a light-transmitting flat substrate 1, a light-transmitting substantially conical optical probe 3 formed so as to protrude on one surface of the flat substrate 1, and The flat substrate 1 is composed of a reflective film 2 formed on the surface where the optical probe 3 is provided, excluding the tip of the optical probe 3. The size of the portion of the tip of the optical probe 3 where the reflective film 2 is not formed is on the order of nm.
[0022]
In the above configuration, when information is recorded on the recording medium 300, the intensity of the light from the light source 402 is modulated according to the information. The modulated light is converted into the parallel beam 5 by the collimator lens 401, passes through the beam splitter 400, and is converged on the optical probe 3 by the condenser lens 4.
[0023]
The converged light passes through the flat substrate 1 of the optical probe element 20 and enters the optical probe 3, and is narrowed down to a diameter equal to or smaller than the diffraction limit. That is, the aperture is narrowed down to about the size (nm order) of the opening where the reflection film 2 at the tip of the optical probe 3 is not formed.
[0024]
The minute light 6 obtained by the optical probe 3 is applied to the recording layer 302 of the recording medium 300. The irradiated portion rises in temperature according to the intensity of the minute light 6.
[0025]
If the recording layer 302 is made of a phase change material, the structure changes according to information. If the recording layer 302 is made of a magnetic material, the magnetization state changes according to information. In this way, information is recorded on the recording layer 302.
[0026]
When information is reproduced from the recording medium 300, the intensity is lower than when information is recorded, and certain light is emitted from the light source 402. In the same manner as described above, the minute light 6 obtained by the optical probe 3 is irradiated to the recording layer 302 of the recording medium 300.
[0027]
The return light from the recording layer 302 is captured by the optical probe 3 to become divergent light, and is collected by the condenser lens 4. The collected light is reflected by the beam splitter 400 and guided to the photodetector 403. The photodetector 403 detects the intensity of the return light from the recording layer 302 or the rotation of the polarization plane, and converts it into an electrical signal. Information is reproduced based on this electrical signal.
[0028]
As described above, in the recording / reproducing apparatus of the present embodiment, the minute light 6 from the optical probe 3 is used, so that information can be recorded / reproduced in a region of nm order.
[0029]
Next, variations of the recording / reproducing apparatus (A1) will be described. Each variation is distinguished by subscripted English characters.
[0030]
As shown in FIG. 3, the recording / reproducing apparatus (A2) has a configuration in which the photodetector 403 is arranged on the flat substrate 1 side of the recording medium 300, and reproduces information based on light transmitted through the recording medium 300. To do. According to this, since the necessary beam splitter 400 can be omitted in the recording / reproducing apparatus (A1), the configuration is simplified.
[0031]
As shown in FIG. 4, the recording / reproducing apparatus (A 3) is configured to directly guide light from the optical fiber 404 to the condenser lens 4 instead of light from the light source 402. According to this, since the collimator lens 401 necessary for the recording / reproducing apparatus (A2) can be omitted, the configuration is further simplified.
[0032]
As a reference example for the present invention In the recording / reproducing apparatus (A4), as shown in FIG. 5, the base 200 is made of a translucent material, and the entire surface of the recording medium 300 is irradiated with uniform light 405 from the base 200 side. The light detector 403 is disposed on the side opposite to the optical probe element 20 side of the condenser lens 4 and reproduces information by picking up the transmitted light of the recording medium 300 with the optical probe 3. According to this, compared with the recording / reproducing apparatuses (A1) to (A3) in which the minute light 6 is incident on the recording medium 300, a reproducing apparatus having a simple configuration can be realized.
[0033]
As a reference example for the present invention As shown in FIG. 6, the recording / reproducing apparatus (A5) sets the incident angle so that the uniform light 405 incident on the recording medium 300 is totally reflected by the recording medium 300, and emits evanescent light leaking from the recording medium 300. Information is reproduced by detecting the information. Thereby, similarly to the playback device (A4), a playback device with a simple configuration can be realized.
[0034]
As a reference example for the present invention As shown in FIG. 7, the recording / reproducing apparatus (A6) has a configuration in which an optical probe element 20 having a plurality of optical probes 3 is provided in the recording / reproducing apparatus (A4, A5). In this optical probe element 20, as shown in FIG. 8, optical probes 3 ... are two-dimensionally arranged. This makes it possible to record and reproduce information using the optical probes 3... Closest to the part to be accessed on the recording medium 300, so that high-speed recording and reproduction can be performed. Further, simultaneous recording, simultaneous reproduction, or simultaneous recording and simultaneous reproduction can be performed on a plurality of portions on the recording medium 300, so that higher speed recording and reproduction can be performed.
[0035]
Next, the manufacturing method of said optical probe element 20 is demonstrated. There are variations in the manufacturing method, and these are distinguished by subscripted English letters.
[0036]
In the manufacturing method (P11), as shown in FIG. 9, first, a mask 10 made of a photoresist is formed at a position where the optical probe 3 is to be formed on the planar substrate 1 (FIG. 9A). The diameter of the mask 10 is 4 to 20 μm as will be described later. Next, the planar substrate 1 is isotropically etched (FIGS. (B) and (c)). The planar substrate 1 under the mask 10 is under-etched, and the mask 10 is released. As a result, a substantially conical protrusion 21 having a sharp tip is formed on the flat substrate 1.
[0037]
Next, the reflective film 2 is formed on the surface of the flat substrate 1 on which the protrusions 21 are formed ((d) in the figure). Then, the reflection film 2 at the tip portion of the protrusion 21 is removed (FIG. 5E).
[0038]
Thereby, the optical probe 3 is formed on the flat substrate 1.
[0039]
The removal of the reflective film 2 at the tip portion of the protrusion 21 can be performed by any one of the following three methods or a combination thereof.
[0040]
In the removal method (E1), the projection 21 is irradiated with strong light from the flat substrate 1 side. Thereby, the reflective film 2 at the tip portion of the protrusion 21 is evaporated.
[0041]
In the removal method (E2), the protrusion 21 is disposed close to the conductor. Then, by detecting a tunnel current between the protrusion 21 and the conductor, a large current that causes temporary field emission is repeatedly passed while controlling the distance between the protrusion 21 and the conductor. Thereby, the reflective film 2 at the tip portion of the protrusion 21 is evaporated.
[0042]
In the removal method (E3), electric field etching is performed. Since the electric field concentrates on the tip portion of the protrusion 21, etching is performed only here.
[0043]
In the above manufacturing method (P11), the mask 10 is preferably circular in shape so that the optical probe 3 narrows down the light more efficiently. Moreover, in order for the optical probe 3 to receive all the light narrowed down by the condensing lens 4, it is preferable that the diameter of the mask 10 is 4-20 micrometers.
[0044]
When glass such as quartz glass or aluminosilicate glass is used for the flat substrate 1, it is preferable to perform isotropic etching by wet etching using buffered hydrofluoric acid in which hydrofluoric acid and ammonium fluoride are mixed.
[0045]
Next, the specific example of said manufacturing method (P11) is shown.
[0046]
A mask 10 made of a circular photoresist having a thickness of 1 μm and a diameter of 10 μm is formed on one surface of a flat substrate 1 made of aluminosilicate glass, and wet etching using buffered hydrofluoric acid mixed with hydrofluoric acid and ammonium fluoride. Thus, the protrusion 21 was formed by performing isotropic etching. Then, a reflective film 2 of W was formed, and electric field etching was performed by applying a voltage to the reflective film 2 in a KOH solution, thereby removing the reflective film 2 at the tip portion of the protrusion 21. Thereby, the optical probe 3 having an opening having a diameter of about 10 nm at the tip of the protrusion 21 was formed.
[0047]
The optical probe element 20 was set in a recording / reproducing apparatus (FIG. 1), and a recording / reproducing test was performed.
[0048]
For the recording layer 302 of the recording medium 300, amorphous InSbTe having a film thickness of 40 nm was used. While moving the optical probe 3 by the driving unit 201, a laser beam pulse of 5 mW was guided to the optical probe 3 from the light source 402 made of a semiconductor laser, and irradiated to the recording medium 300. As a result, crystallized regions were formed in the recording layer 302 in a flying manner. The size of each crystallized region was about 10 nm. That is, the size of each region was almost equal to the size of the opening of the optical probe 3. From this result, it was found that information can be recorded with high density by the optical probe 3.
[0049]
Next, a constant laser beam of 1 mW was guided to the optical probe 3 and scanned along the crystallized region. As a result, a pulsed signal was obtained from the photodetector 403. That is, since the reflectance differs between the amorphous region and the crystalline region, a pulse-like signal was obtained. From this result, it was found that information recorded with high density by the optical probe 3 can be reproduced.
[0050]
In the manufacturing method (P12), as shown in FIG. 10, after a mask 10 made of photoresist is formed at a position where the optical probe 3 is to be formed on the flat substrate 1, post baking is performed at a temperature equal to or higher than the deformation temperature of the photoresist. To do. Due to the surface tension acting between the photoresist and the planar substrate 1, the mask 10 becomes a substantially conical mask 11 with a sharp tip (FIG. 5A).
[0051]
Then, anisotropic etching is performed until the mask 11 disappears (FIGS. (B) and (c)). As a result, a substantially conical protrusion 21 having a sharp tip, similar to the mask 11, is formed.
[0052]
Subsequent processes (FIGS. (D) to (e)) are the same as the processes (FIGS. 9 (d) to (e)) of the manufacturing method (P11).
[0053]
When glass such as quartz glass or aluminosilicate glass is used for the flat substrate 1, CF _Four , CHF _Three It is preferable to perform anisotropic etching by dry etching using an etching gas such as.
[0054]
Next, the specific example of said manufacturing method (P12) is shown.
[0055]
A mask 10 made of a circular photoresist having a thickness of 5 μm and a diameter of 5 μm is formed on one surface of a flat substrate 1 made of quartz glass, and the temperature is raised to 150 ° C., which is equal to or higher than the deformation temperature of the photoresist. Baking for a minute. As a result, the mask 10 became a substantially conical mask 11 with a sharp tip. CF _Four Dry etching using was performed until the mask 11 disappeared, and the protrusions 21 were formed. Then, a reflection film 2 of W was formed, and electric field etching was performed in a KOH solution, whereby the optical probe 3 having an opening having a diameter of about 20 nm at the tip of the protrusion 21 could be formed.
[0056]
The optical probe element 20 was set in a recording / reproducing apparatus (FIG. 3), and a recording / reproducing test was performed. Test conditions are as described above. As a result, a crystallized region of about 20 nm can be formed, and the reproduction can be performed well.
[0057]
In the manufacturing method (P13), as shown in FIG. 11, a mask 10 made of a photoresist is formed at a position where the optical probe 3 is to be formed on the planar substrate 1 (FIG. 11A). This method is different from the manufacturing method (P11) in that etching is performed (FIG. 5B). Since the flat substrate 1 is etched except for the flat substrate 1 under the mask 10, the step 40 is formed on the flat substrate 1.
[0058]
Subsequent processes (FIGS. (C) to (f)) are the same as the processes (FIGS. 9B to 9E) of the manufacturing method (P11).
[0059]
In this manufacturing method (P13), since the protrusion 21 is formed in step 40, the protrusion 21 is sharper compared to the manufacturing method (P11). Thereby, the opening part of the front-end | tip of the optical probe 3 can be made smaller.
[0060]
Next, the specific example of said manufacturing method (P13) is shown.
[0061]
A mask 10 made of a circular photoresist having a thickness of 5 μm and a diameter of 5 μm is formed on one side of the flat substrate 1 made of quartz glass, and the exposed flat substrate 1 is made CF. _Four Step 40 having a step of about 4 μm was formed by dry etching using Next, isotropic etching was performed by wet etching using buffered hydrofluoric acid to form the protrusions 21. Then, a reflective film 2 of W was formed, and a voltage was applied to the reflective film 2 to perform electric field etching in a KOH solution, thereby removing the reflective film 2 at the tip portion of the protrusion 21. Thereby, the optical probe 3 having an opening having a diameter of about 5 nm at the tip of the protrusion 21 was formed.
[0062]
The optical probe element 20 was set in a recording / reproducing apparatus (FIG. 1), and a recording / reproducing test was performed. Test conditions are as described above (however, the film thickness of the recording layer 302 is 20 nm). As a result, a crystallized region of about 5 nm could be formed, and the reproduction was also good.
[0063]
In the manufacturing method (P14), as shown in FIG. 12, in the same manner as in the manufacturing method (P12), a substantially conical mask 11 with a sharp tip is formed at a position where the optical probe 3 is to be formed on the flat substrate 1. Is formed ((a) in the figure).
[0064]
Subsequent processes (FIGS. (B) to (e)) are the same as the processes (FIGS. 11 (d) to (f)) of the manufacturing method (P13).
[0065]
In this manufacturing method (P14), since the protrusion 21 is formed in the substantially truncated cone-shaped step 41, the protrusion 21 having a smooth conical surface is obtained as compared with the manufacturing method (P13). Thereby, light can be more efficiently guided to the tip of the optical probe 3.
[0066]
Next, the specific example of said manufacturing method (P14) is shown.
[0067]
A mask 10 made of a circular photoresist having a thickness of 5 μm and a diameter of 5 μm is formed on one surface of a flat substrate 1 made of quartz glass, and the temperature is raised to 150 ° C., which is equal to or higher than the deformation temperature of the photoresist. Baking for a minute. As a result, the mask 10 became a substantially conical mask 11 with a sharp tip. CF _Four Step 41 having a step of about 4 μm was formed by dry etching using Next, isotropic etching was performed by wet etching using buffered hydrofluoric acid to form the protrusions 21. Then, a reflective film 2 of W was formed, and a voltage was applied to the reflective film 2 to perform electric field etching in a KOH solution, thereby removing the reflective film 2 at the tip portion of the protrusion 21. Thereby, the optical probe 3 having an opening having a diameter of about 5 nm at the tip of the protrusion 21 was formed.
[0068]
The optical probe element 20 was set in a recording / reproducing apparatus (FIG. 3), and a recording / reproducing test was performed. Test conditions are as described above (however, the film thickness of the recording layer 302 is 20 nm). As a result, a crystallized region of about 5 nm could be formed, and the reproduction was also good.
[0069]
In the manufacturing method (P15), as shown in FIG. 13, first, after the adhesion enhancement layer 7 is formed on the flat substrate 1, the mask 10 made of photoresist is formed at the position where the optical probe 3 is to be formed. It differs from the said manufacturing method (P11) by the point (the figure (a)).
[0070]
Thereafter, the exposed adhesion reinforcing layer 7 is removed by etching (FIG. 5B). Subsequent processes (FIGS. (C) to (f)) are the same as the processes (FIGS. 9B to 9E) of the manufacturing method (P11).
[0071]
In this manufacturing method (P15), since the adhesion enhancement layer 7 is provided between the flat substrate 1 and the mask 10, the mask 10 is difficult to peel off from the flat substrate 1. Thereby, the protrusion 21 can be formed reliably.
[0072]
For the adhesion enhancement layer 7, it is preferable to use a material that is not etched in the process of isotropic etching of the flat substrate 1 ((c) in the figure). For example, when glass is used for the flat substrate 1 and isotropic etching is performed by wet etching using buffered hydrofluoric acid, Ta, Au, Pt, etc. that are not etched with buffered hydrofluoric acid are used as the adhesion enhancing layer 7. It is preferable to use these materials. However, the material is not particularly limited as long as the material is less likely to be etched than the flat substrate 1.
[0073]
Next, a specific example of the production method (P15) will be shown.
[0074]
After the adhesion enhancing layer 7 made of Ta having a thickness of 50 nm is formed on one surface of the flat substrate 1 made of aluminosilicate glass, a mask 10 made of a circular photoresist having a thickness of 1 μm and a diameter of 10 μm is formed. The exposed adhesion reinforcing layer 7 was removed by dry etching using CF4. Next, isotropic etching was performed by wet etching using buffered hydrofluoric acid to form the protrusions 21. Then, a reflective film 2 of W was formed, and a voltage was applied to the reflective film 2 to perform electric field etching in a KOH solution, thereby removing the reflective film 2 at the tip portion of the protrusion 21. Thereby, the optical probe 3 having an opening having a diameter of about 10 nm at the tip of the protrusion 21 was formed.
[0075]
This optical probe element 20 was set in a recording / reproducing apparatus (FIG. 4), and a recording / reproducing test was performed. Test conditions are as described above. As a result, a crystallized region of about 10 nm could be formed, and the reproduction was also good.
[0076]
Next, variations of the optical probe element 20 will be described.
[0077]
As shown in FIG. 14, the optical probe element 20 (P2) has a configuration in which the optical probe 3 is formed in the concave portion 1 a of the flat substrate 1. On the other hand, the optical probe element 20 (P1) has a configuration in which the optical probe 3 is formed so as to protrude on one surface of the flat substrate 1.
[0078]
Hereinafter, a method for manufacturing the optical probe element 20 (P2) will be described.
[0079]
In the manufacturing method (P21), as shown in FIG. 15, first, a mask 12 made of a photoresist is formed except the position where the optical probe 3 is to be formed on the planar substrate 1 (FIG. 15A). The diameter of the portion 60 of the flat substrate 1 without the mask 12 is 1 to 5 μm, as will be described later. Next, the flat substrate 1 is isotropically etched to form a recess 1a (FIG. 2B). At this time, not only the portion 60 of the planar substrate 1 is etched, but also the vicinity of the portion 60 of the planar substrate 1 under the mask 10 is under-etched.
[0080]
Next, a transparent dielectric material is sputtered. As a result, a transparent film 8 made of a transparent dielectric material is formed on the mask 12, and a substantially conical protrusion 21 made of a transparent dielectric material and having a sharp tip is formed in the recess 1a ( (C) in the figure. That is, since the transparent dielectric material particles are deposited from various directions in the recess 1a, the protrusion 21 is formed.
[0081]
Next, after removing the transparent film 8 together with the mask 12, the reflective film 2 is formed on the surface of the flat substrate 1 on which the protrusions 21 are formed ((d) in the figure). Then, the reflection film 2 at the tip portion of the protrusion 21 is removed (FIG. 5E). Thereby, the optical probe 3 is formed on the flat substrate 1.
[0082]
In the manufacturing method (P21), the shape of the portion 60 is preferably circular in order for the optical probe 3 to narrow down the light more efficiently. Further, in order to form the substantially conical protrusion 21 having a sharp tip, the diameter of the portion 60 is preferably 1 to 5 μm.
[0083]
The transparent dielectric material is the same material as the planar substrate 1 (for example, SiO 2 ₂ , SiO). However, AlN, Si _Three N _Four TiO ₂ Etc. can also be used.
[0084]
Next, the specific example of said manufacturing method (P21) is shown.
[0085]
A mask 12 made of a photoresist having a thickness of 1 μm is formed on one surface of the flat substrate 1 made of quartz glass except for a portion 60 of the circular flat substrate 1 having a diameter of 2 μm, and wet etching using buffered hydrofluoric acid is performed. Thus, isotropic etching was performed to form the recess 1a. Next, SiO ₂ As a result, a transparent film 8 having a thickness of 5 μm was formed on the mask 12, and a protrusion 21 was formed in the recess 1a. Then, the transparent film 8 was removed together with the mask 12, the W reflective film 2 was formed, and the reflective film 2 at the tip portion of the protrusion 21 was removed by electric field etching. Thereby, the optical probe 3 having an opening having a diameter of about 5 nm at the tip of the protrusion 21 was formed.
[0086]
The optical probe element 20 was set in a recording / reproducing apparatus (FIG. 1), and a recording / reproducing test was performed. Test conditions are as described above (however, the film thickness of the recording layer 302 is 20 nm). As a result, a crystallized region of about 5 nm could be formed, and the reproduction was also good.
[0087]
In the manufacturing method (P22), as shown in FIG. 16, after the mask 12 is formed (FIG. 16A), first, anisotropic etching is performed (FIG. 16B). Different from P21).
[0088]
Subsequent processes (FIGS. (C) to (f)) are the same as the processes (FIGS. 15 (b) to (e)) of the manufacturing method (P21).
[0089]
In this manufacturing method (P22), since the concave portion 1a is formed by performing isotropic etching after anisotropic etching, the concave portion 1a is more accurately compared with the manufacturing method (P21). Can be formed.
[0090]
Next, the specific example of said manufacturing method (P22) is shown.
[0091]
A mask 12 made of a photoresist having a thickness of 4 μm is formed on one surface of the flat substrate 1 made of quartz glass, except for a portion 60 of the circular flat substrate 1 having a diameter of 3 μm, and CF _Four After performing anisotropic etching to a depth of 3 μm by dry etching using, isotropic etching was performed by wet etching using buffered hydrofluoric acid to form a recess 1 a having a depth of 5 μm. Next, SiO ₂ As a result, a transparent film 8 having a thickness of 5 μm was formed on the mask 12, and a protrusion 21 was formed in the recess 1a. Then, the transparent film 8 was removed together with the mask 12, the W reflective film 2 was formed, and the reflective film 2 at the tip portion of the protrusion 21 was removed by electric field etching. Thereby, the optical probe 3 having an opening having a diameter of about 5 nm at the tip of the protrusion 21 was formed.
[0092]
The optical probe element 20 was set in a recording / reproducing apparatus (FIG. 3), and a recording / reproducing test was performed. Test conditions are as described above (however, the film thickness of the recording layer 302 is 20 nm). As a result, a crystallized region of about 5 nm could be formed, and the reproduction was also good.
[0093]
The present invention Second embodiment of This will be described with reference to FIGS. 17 to 26. For convenience of explanation, members having the same functions as those shown in the drawings of the above-described embodiment are given the same reference numerals, and explanation thereof is omitted.
[0094]
Example This recording / reproducing apparatus is different from the above-described embodiment in that an optical probe element 20 having a microlens 100 is provided as shown in FIG. For comparison, FIG. 18 shows a recording / reproducing apparatus that replaces the optical probe element 20 without the microlens 100.
[0095]
Example In the recording / reproducing apparatus, since the microlens 100 plays the role of the condenser lens 4, the external condenser lens 4 becomes unnecessary and the configuration is simplified.
[0096]
As shown in FIG. 19, the optical probe element 20 includes a light-transmitting flat substrate 1, a light-transmitting substantially conical optical probe 3 formed so as to protrude on one surface of the flat substrate 1, and a flat substrate. 1 on the surface on which the optical probe 3 is provided, the reflective film 2 formed by removing the tip of the optical probe 3, and the surface of the flat substrate 1 opposite to the surface on which the optical probe 3 is provided The microlens 100 is formed at a position facing the optical probe 3. The size of the portion of the tip of the optical probe 3 where the reflective film 2 is not formed is on the order of nm. The microlens 100 is formed so that the optical probe 3 is located at the focal point so that the light from the optical probe 3 can be efficiently collected.
[0097]
The recording / reproducing apparatus shown in FIG. 20 is a variation of the above-described recording / reproducing apparatus, and includes an optical probe element 20 having a plurality of optical probes 3 and a plurality of microlenses 100 corresponding thereto. In this optical probe element 20, as shown in FIG. 21, optical probes 3 ... and micro lenses 100 ... are two-dimensionally arranged. According to this, high-speed recording / reproduction can be performed with a simple configuration.
[0098]
When the optical probe element 20 is manufactured, as shown in FIG. 22, first, the microlens 100 is formed on one surface of the flat substrate 1 (FIG. 22A). Then, the optical probe 3 is formed on the surface of the flat substrate 1 on the side where the microlens 100 is not formed. The process of forming the optical probe 3 (FIGS. (B) to (f)) is the same as the process (FIGS. 9A to 9E) of the manufacturing method (P11) of the above embodiment.
[0099]
An optical probe element 20 shown in FIG. 23 is a variation of the optical probe element 20 described above, and has a configuration in which the optical probe 3 is formed in the recess 1 a of the flat substrate 1.
[0100]
When the optical probe element 20 is manufactured, as shown in FIG. 24, first, the microlens 100 is formed on one surface of the flat substrate 1 (FIG. 24A). Then, the optical probe 3 is formed on the surface of the flat substrate 1 on the side where the microlens 100 is not formed. The process of forming the optical probe 3 (FIGS. (B) to (f)) is the same as the process (FIGS. 15 (a) to (e)) of the manufacturing method (P21) of the above embodiment.
[0101]
The micro lens 100 of the optical probe element 20 may be replaced with a Fresnel lens 110 as shown in FIGS. Similar to the microlens 100, the Fresnel lens 110 is formed so that the optical probe 3 is located at the focal point so that the light from the optical probe 3 can be efficiently collected.
[0102]
In addition, Example In the manufacturing method of the optical probe element 20, the process after forming the microlens 100 or the Fresnel lens 110 on the flat substrate 1 is the same as the manufacturing method of the above-described embodiment, so that all of them can be used.
[0103]
The above optical probe element 20 was set in a recording / reproducing apparatus (FIG. 17), and a recording / reproducing test was performed. The test conditions are the same as in the previous example. As a result, a crystallized region substantially equal to the size of the opening of the optical probe 3 (about 10 nm) could be formed in the recording layer 302, and reproduction was also good.
[0104]
Further, a recording / reproducing test was performed by setting the optical probe element 20 having the plurality of optical probes 3 to the recording / reproducing apparatus (FIG. 20). The test conditions are the same as in the previous example. As a result, a crystallized region substantially equal to the size of the opening of the optical probe 3 (about 10 nm) could be formed in the recording layer 302, and reproduction was also good. Furthermore, by providing a photodetector 403 corresponding to each optical probe 3, information can be reproduced simultaneously.
[0105]
More than Example In this case, if a large number of optical probes 3 are formed on a planar substrate 1 larger than the optical probe element 20, and then the planar substrate 1 having the required number of optical probes 3 is cut out, the optical probe can be efficiently obtained. The element 20 can be manufactured.
[0106]
As above Second embodiment The optical probe element includes a substantially conical protrusion made of a translucent material, and an optical probe made of a reflective film formed on the conical surface of the protrusion excluding the tip portion of the protrusion, and a planar substrate made of a translucent material And the other surface of the planar substrate is planar, and the light collecting means for focusing on the optical probe is formed on the planar substrate surface on the side where the optical probe is not formed. There is an effect that it is not necessary to install a condensing means such as an objective lens outside.
[0107]
further, Second embodiment As described above, the optical probe element is the above-described optical probe element, and the condensing means is either a single lens or a Fresnel lens. There is an effect that can be realized.
[0108]
Also, Second embodiment As described above, the recording / reproducing apparatus includes a light source and an optical probe element that narrows light from the light source to minute light having a diameter less than or equal to the diffraction limit, and records and reproduces information by irradiating the recording medium with minute light. In the recording / reproducing apparatus for performing the above, the optical probe element includes a substantially conical protrusion made of a translucent material, and an optical probe made of a reflective film formed on the conical surface of the protrusion except for the tip portion of the protrusion. A flat surface formed on one side of a flat substrate made of a light-transmitting material, and the other surface of the flat substrate is flat, and the condensing means for focusing on the optical probe is a flat surface on which the optical probe is not formed. Since it is formed on the substrate surface, the recording / reproducing apparatus can be efficiently mass-produced.
[0109]
further, Second embodiment As described above, the recording / reproducing apparatus is the above-described recording / reproducing apparatus, in which a plurality of optical probes are formed on one surface of a flat substrate, and the same number of optical probes are focused on each optical probe. Since the optical means is formed on the plane substrate surface on the side where the optical probe is not formed, it is possible to simultaneously record and reproduce a plurality of information, and to collect light such as an objective lens outside the optical probe element. There is an effect that it is not necessary to install means.
[0110]
【The invention's effect】
The present invention As described above, the optical probe element according to the present invention includes a substantially conical protrusion made of a light-transmitting material and a reflection film formed on the conical surface of the protrusion excluding the tip of the protrusion. The other surface of the planar substrate is formed in a planar shape, and the projection of the optical probe is formed by etching one surface of the planar substrate. The converged light collected by the condenser lens is incident on the planar substrate from a planar portion facing the projection of the optical probe, and is transmitted through the planar substrate and incident on the projection. It is possible to form an optical probe on a flat substrate using As a result, it is possible to efficiently mass-produce optical probe elements that meet the standards.
[0111]
The present invention As described above, the optical probe element according to the above Since a plurality of optical probes are formed on one side of a flat substrate, the above In addition to the above effect, it is possible to record and reproduce a plurality of information simultaneously.
[0112]
The present invention As described above, the optical probe element according to the above-mentioned optical probe element is a plane on the side where the optical probe is not formed, and the same number of condensing means as the optical probes are focused on each optical probe. Since it is formed on the substrate surface, in addition to the above-described effect, there is an effect that it is not necessary to install a condensing means such as an objective lens outside.
[0113]
The present invention As described above, the recording / reproducing apparatus according to the present invention includes a light source and an optical probe element that narrows light from the light source to minute light having a diameter less than the diffraction limit, and records information by irradiating the recording medium with minute light. In a recording / reproducing apparatus that performs reproduction, the optical probe element includes a substantially conical protrusion made of a light-transmitting material and a reflection probe formed on a conical surface of the protrusion except for a tip portion of the protrusion. Formed on one side of a flat substrate made of a translucent material, and the other surface of the flat substrate is flat, and the projection of the optical probe is formed by etching one side of the flat substrate. The converged light converged by the condensing lens is incident on the planar substrate from a planar portion facing the projection of the optical probe, and is transmitted through the planar substrate and incident on the projection. Recording / playback An effect that it becomes possible to mass-produce the location efficiently.
[Brief description of the drawings]
FIG. 1, illustrating a first embodiment of the present invention, is an explanatory diagram illustrating a schematic configuration of a recording / reproducing apparatus.
FIG. 2 is an explanatory diagram showing a schematic configuration of an optical probe element in the recording / reproducing apparatus of FIG. 1;
FIG. 3 is an explanatory view showing a variation of the recording / reproducing apparatus of FIG. 1;
4 is an explanatory diagram showing another variation of the recording / reproducing apparatus of FIG. 1. FIG.
[Figure 5] As a reference example for the present invention Recording / playback equipment Place It is explanatory drawing shown.
[Fig. 6] As a reference example for the present invention It is explanatory drawing which shows the other variation of a recording / reproducing apparatus.
[Fig. 7] As a reference example for the present invention It is explanatory drawing which shows the other variation of a recording / reproducing apparatus, and has shown the recording / reproducing apparatus provided with the optical probe element which consists of a some optical probe.
8A and 8B are explanatory views showing a schematic configuration of the optical probe element in the recording / reproducing apparatus of FIG. 7, in which FIG. 8A is a plan view and FIG. 8B is a front view.
9 is an explanatory view showing a method of manufacturing the optical probe element of FIG. 2, and FIGS. 9A to 9E show each process. FIG.
10 is an explanatory view showing another method of manufacturing the optical probe element of FIG. 2, and FIGS. 10A to 10E show each process. FIG.
11 is an explanatory view showing another method of manufacturing the optical probe element of FIG. 2, and FIGS. 11 (a) to (f) show each process. FIG.
12 is an explanatory view showing another method for manufacturing the optical probe element of FIG. 2, and FIGS. 12A to 12E show each process. FIG.
13 is an explanatory view showing another method of manufacturing the optical probe element shown in FIG. 2, and FIGS. 13A to 13F show each process.
14 is an explanatory diagram showing a schematic configuration of another optical probe element in the recording / reproducing apparatus of FIG. 1. FIG.
15 is an explanatory view showing a manufacturing method of the optical probe element of FIG. 14, and FIGS.
16 is an explanatory view showing another method of manufacturing the optical probe element shown in FIG. 14, and FIGS. 16A to 14F show each process.
FIG. 17 shows the present invention. Second embodiment of FIG. 2 is an explanatory diagram showing a schematic configuration of a recording / reproducing apparatus.
18 shows a comparative example of the recording / reproducing apparatus in FIG. 17, and is an explanatory diagram showing a schematic configuration of the recording / reproducing apparatus.
FIG. 19 is an explanatory diagram showing a schematic configuration of an optical probe element in the recording / reproducing apparatus of FIG. 17;
20 is an explanatory view showing a variation of the recording / reproducing apparatus of FIG. 17, and shows a recording / reproducing apparatus provided with an optical probe element composed of a plurality of optical probes.
FIG. 21 is a front view showing a schematic configuration of an optical probe element in the recording / reproducing apparatus of FIG. 20;
22 is an explanatory view showing a method of manufacturing the optical probe element of FIG. 19, and FIGS. (A) to (f) show each process.
FIG. 23 is an explanatory diagram showing a schematic configuration of another optical probe element in the recording / reproducing apparatus of FIG. 17;
24 is an explanatory view showing a manufacturing method of the optical probe element of FIG. 23, wherein FIGS. (A) to (f) show each process. FIG.
25 is an explanatory diagram showing a schematic configuration of another optical probe element in the recording / reproducing apparatus of FIG.
FIG. 26 is an explanatory diagram showing a schematic configuration of another optical probe element in the recording / reproducing apparatus of FIG.
FIG. 27 is an explanatory diagram showing a schematic configuration of a conventional recording / reproducing apparatus.
28 is an explanatory view showing a method of manufacturing the optical probe of FIG. 27, wherein FIGS. (A) to (c) show each process.
[Explanation of symbols]
1 Planar substrate
1a recess
2 reflective film
3 Optical probe
6 Micro light
7 Adhesion strengthening layer
8 Transparent film
10 Mask
11 Mask
12 Mask
20 Optical probe elements
21 Protrusions
100 micro lens
110 Fresnel lens
300 recording media
302 Recording medium layer
402 Light source

Claims (4)

A substantially conical protrusion made of a translucent material and an optical probe made of a reflective film formed on the conical surface of the protrusion excluding the tip of the protrusion are formed on one side of a flat substrate made of a translucent material, And the other surface of the planar substrate is planar,
The projection of the optical probe is formed by etching one side of the flat substrate,
Converged light converged by a condensing lens is incident on the planar substrate from a planar portion facing the projection of the optical probe, passes through the planar substrate, and is incident on the projection. element. 2. The optical probe element according to claim 1, wherein a plurality of optical probes are formed on one side of a flat substrate. 3. The optical probe element according to claim 2, wherein the same number of condensing means as the optical probes, each of which is focused on each optical probe, are formed on the plane substrate surface on the side where the optical probes are not formed. In a recording / reproducing apparatus that includes a light source and an optical probe element that narrows light from the light source to minute light having a diameter equal to or less than a diffraction limit, and records and reproduces information by irradiating the recording medium with minute light.
  The above-described optical probe element has a substantially conical protrusion made of a light-transmitting material and a light probe made of a reflective film formed on the conical surface of the protrusion excluding the tip of the protrusion. Formed on one side of the substrate and the other side of the planar substrate is planar,
  The projection of the optical probe is formed by etching one side of the flat substrate,
  Condensed light converged by a condensing lens is incident on the planar substrate from a planar portion facing the projection of the optical probe, passes through the planar substrate, and is incident on the projection. apparatus.

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